Apparatus for chemical testing

ABSTRACT

A reagent container having a series of tiered compartments containing prepackaged reagents for the chemical evaluation of a test sample. A frangible diaphragm seals each compartment from the succeeding compartment. A sample is introduced into the top compartment. After incubation a breaker punctures the seal of the adjacent compartment, allowing the reagents to mix and react. The procedure is repeated for each reagent filled compartment.

United States Patent [191 Shapiro 1 Jan. 30, 1973 [54] APPARATUS FORCHEMICAL TESTING [75] lnventor: Stephen Shapiro, East Bridgewater,

Mass.

[73] Assignee: Becton, Dickinson and Company,

East Rutherford, NJ.

[22] Filed: Feb. 1,1971

[21] Appl. N0.: 111,360

[52] US. Cl. ..23/259, 23/253 R, 206/47 A [51] Int. Cl. ..G0ln 1/16,865d 79/00 [58] Field of Search ..23/292, 253, 259, 230;

[56] References Cited UNITED STATES PATENTS 3,446,596 5/1969 Salivar etal. ..23/253 X 3,477,822 11/1969 Hamilton ..23/292 X 3,480,398 11/1969Hamilton 3,497,320 2/1970 Blackburn et al. 3,554,705 1/1971 Johnston etal ..23/292 X Primary ExaminerMorris O Wolk Assistant ExaminerR. E.Serwin AttorneyKane, Dalsimer, Kane, Sullivan and Kurucz [57] ABSTRACT Areagent container having a series of tiered compartments containingprepackaged reagents for the chemical evaluation of a test sample. Afrangible diaphragm seals each compartment from the succeedingcompartment. A sample is introduced into the top compartment. Afterincubation a breaker punctures the seal of the adjacent compartment,allowing the reagents to mix and react. The procedure is repeated foreach reagent filled compartment.

4 Claims, 4 Drawing Figures APPARATUS FOR CHEMICAL TESTING BACKGROUND OFTHE INVENTION 1. Field of the Invention The present invention isdirected to an apparatus and method for performing a chemical evaluationof a material employing prepackaged reagents. In particular, it relatesto a tiered reagent cup for storing prepackaged reagents and puncturingand mixing means for sequentially exposing a material to be tested tothe prepackaged reagents.

2. Description of the Prior Art In order to perform a chemicalevaluation of a serum or other material in the field, it has provennecessary to employ a series of reagent containers. Often a conventionalpipetting device is employed to transfer reagents, sequentially, to areaction chamber in order to test a serum or other material for variousproperties. This procedure has several major defects. With manualpipetting, reagent volume is always subject to variation. It is alsocumbersome to store and clean a series of reagent containers which areto be taken into the field. Prior art compartmented devices for storingreagents have proven, for the most part, unsatisfactory.

In U.S. Pat. Nos. 2,568,029 029 and 2,753,868, a container having aseries of compartments is provided for storing ingredients suitable forhypodermic injection. Owing to the narrow-neck compartment design, it isdifficult to load the compartments with reagents.

The odd-shaped necks of the compartments have proven difficult to seal,as evidenced by the cumbersome drop method for providing septa.

Further, the narrow-necked compartment design prevents adequate mixingof the reagents. Even more important, it is necessary to employ ahypodermic syringe for introducing or removing reagents from thecompartments, once the unit is sealed.

Certain prior art devices provide a receptacle for the mixing ofreagents prepackaged therein, but do not permit introduction of amaterial to be tested into the compartments. Such a device isillustrated in U.S. Pat. No. 3,415,360. The non-unitary nature of thereceptacle makes it difficult to assemble. The rigid cap prohibitsaddition of a serum or the like to the top, reagent-containing chamber.

Certain prior art reagent-containing devices are formed wherein areagent-containing cylindrical insert is spaced within an outerreceptacle. Such devices provide various problems in fabrication, sincethe insert must be correctly positioned and supported by some externalsupport mechanism. In many cases the inserts are sealed by aself-supporting membrane. Such a membrane can be difficult to ruptureduring mixing of the reagents. Illustrative of such prior art devices isthe insulating device disclosed in U.S. Pat. No. 3,359,361.

SUMMARY OF THE INVENTION It is, therefore, the primary object of theinvention to provide a reagent-containing device particularly adapted toevaluate a test sample by the sequential addition of reagents to thetest sample.

It is another object of the invention to provide a reagent-containingtest device which can be accurately prefilled with reagent and which isof simple design and easily fabricated.

It is an additional object of the invention to provide a device havingprepackaged reagents and adapted for the sequential addition of reagentsto a test material which also provides enhanced mixing of each of thereagents with the test sample.

It is a further object of the invention to provide a method forintroducing a test sample into a reaction chamber containing aprepackaged reagent and thereafter mixing the sample and first reagentwith at least one further reagent for further testing.

The above and other objects are met in a unitary tiered reagent cup. Thetiered cup has a series of hollow cylinders. The bottom cylinder or basereceptacle is closed at one end. The diameter of each cylindrical tieris progressively greater from the bottom to the top of the cup. Eachstepped tier is hermetically sealed by a frangible diaphragm whichoverlies the cylindrical tier and is supported by the step resultingfrom the diametrical increase of the next larger tier. The frangiblediaphragm, therefore, serves to seal the top of one cylindrical tier andbecomes the bottom of the cylindrical tier spaced immediatelythereabove. The reagent cup may be fabricated with as many tiers, asdesired. The top of the reagent cup is hermetically sealed by afrangible diaphragm which is supported by a final step.

In order to fill the cup with reagents, a manual or automatic meteringdevice dispenses a pre-selected quantity of reagent into the basereceptacle. The receptacle is then sealed by the frangible diaphragm.This procedure is repeated for each succeeding cylindrical tieremploying the same or different reagents in each tier. The top tier issealed by a frangible diaphragm to complete a prepackaged reagent cup.

In use, a test sample is introduced into the top compartment through ahollow needle which is adapted to make a small puncture in the frangibletop cover. After a suitable incubation period a breaker means rupturesthe seal forming the base of the top compartment, thereby allowing thecontents of the top and next succeeding compartment to mix.

After a suitable time the breaker means is employed to rupture the sealforming the base of the second compartment from the top, therebyallowing the contents of the top and next succeeding compartment to mixwith the contents of the compartment immediately thereinbelow. Thisprocedure is repeated until all the frangible seals have been broken.

From the above, it is seen that the invention provides a novel apparatusfor prepackaging accurate quantities of various reagents in acombination shipping container and reaction cup. The unitary tieredcontainer is readily fabricated by conventional extrusion techniques orthe like and does not require specially fabricated and mounted inserts.Since the top of the reagent container has a wide opening, it ispossible to employ accurate reagent delivery means to fill eachcompartment with a carefully predetermined quantity of reagent. By hisnovel design, applicant has eliminated the necessity of carrying aseries of reaction flasks and reagent containers for subjecting a testsample to a sequential addition of reagents. Complete mixing of reagentsand test sample is facilitated by the relatively wide openings to thecompartments. Further, the action of the breaker as it punctures eachsucceeding compartment seal, promotes further enhanced mixing.

The invention will be more fully understood when considered in terms ofthe following description and the accompanying drawing, in which apreferred embodiment of the invention has been illustrated, and inwhich:

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an axial cross-sectional viewof a prepackaged reagentv container, constructed in accordance with theinvention, showing the prepackaged reagents in separate compartments;

FIG. 2 is a view similar to FIG. 1, with a thin, hollow tube puncturingthe top seal, illustrating the introduction of a test sample into thetop compartment (as illustrated by the arrows);

FIG. 3 is a view similar to FIG. 1, in which a breaker has punctured theseals of the top and next succeeding compartment of the reagentcontainer, and in which the contents of the second compartment arecirculating into the top compartment illustrated by the upwardlydisposed arrows): and

FIG. 4 is a view similar to FIG. 3 in which the breaker has puncturedtheseal of the base receptacle.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The reagent cup, as illustratedin FIG. 1, includes a container having a series of stepped tiers. Thecontainer is in the form of a stepped hollow cylinder. At the base ofthe container is a receptacle l2 enclosed by an integral flat bottomplate 14.

A flat annular step or shoulder 16 is continuously disposed about theperiphery of the top of the base receptacle 12. In axial alignment withthe base receptacle is a cylindrical section 18 upwardly disposed fromthe outer periphery of shoulder 16. The radius of cylinder 18 is greaterthan the radius of base receptacle 12. The width ofshoulder 16 is equalto the difference between the radius of cylinder 18 and receptacle l2.

Annular shoulder 20 is continuously disposed outwardly from theperiphery of the top edge of cylinder 18. l-Iollow cylinder 22 hasupstanding walls continuously disposed about the periphery of shoulder20. The radius of cylinder 22 is greater than the radius of cylinder 18.Shoulder 20 is equal in length to the difference between the radius ofcylinder 22 and the radius of cylinder 18. Cover seal supporting means24 is continuously disposed about the top edge of cylinder 22. Asillustrated in FIG. l,'cover supporting means 24 forms a flat annularshoulder with respect to cylinder 22.

Container 10 may be formed from rigid, semirigid or flexible materials.Suitable materials include 'thermosetting and thermoplastic polymers;including polystyrene, polyethylene and polypropylene.

In order to provide discrete reagent compartments within container 10frangible seals are provided. The seals are supported by the respectiveannular shoulders of thecontainer. Suitable frangible materials for theseal include thin metal foils and heat-scalable materials, includingpolymeric films, such as cellophane and laminates. The seals should beinert to the reagents employed and impermeable to the liquid reagentsemployed. The thickness of the seal will, of course, vary to some extentwith the diameter of different sized devices. As a practical matter theseal should rupture on the application of an axial force of less thanabout three pounds. Once ruptured, the seal should tear easily toaccommodate the pointed breaker which is preferably employed to rupturethe seal. To facilitate assembly the seal may have impregnated at theouter periphery thereof a suitable adhesive material capable of forminga liquid .impermeable bond with-the container. If desired, a heatactivatable seal may be employed and suitable heating means applied tothe periphery of the seal to form a suitable bond with the container.

As illustrated in FIG.1, a thin plastic diaphragm 26 overlies basereceptacle 12 to form a base compartment 28 in the container. Diaphragm26 acts as a cover for base compartment 28 and as a base for thecompartment of cylinder 18. Diaphragm .28 overlies cylinder 18 formingcompartment 30, a second reagent chamber in the container.

Shoulder 20 forms a seal supporting means for diaphragm 28. Shoulder 16forms a seal supporting means for diaphragm 26.

Cover seal 32 overlies cylinder 22 to form top reagent compartment 34.Container seal 32 is supported by top shoulder 24.

In order to fill the tiered container with suitable reagents, thecontainer is supported by suitable supporting means. Such supportingmeans includes a bracket ofcomplementary configuration with container10, test tube holder means, or an apertured test tube bracket capable ofaccepting and retaining in a perpendicular position, the containerwherein the container is supported across an aperture by top shoulder24. A first reagent is metered into compartment 28 in base receptacle12. Conventional manual or automated reagent delivery means may beemployed. Thereafter, plastic diaphragm 26 is placed on shoulder 16 andadhesively sealed to the shoulder. Next, a second reagent is introducedinto compartment 30 by suitable delivery means. Thereafter, diaphragm 28is emplaced on shoulder 20 and adhesively adhered to the shoulder.Finally, a third reagent is introduced into compartment 34 and coverdiaphragm 32 is bonded to shoulder 24 to form a completed reagent cup.

Of course, the quantity of reagent in each of the respectivecompartments will be dependent, in part, upon the nature of the materialbeing tested and of the quantity of material added to the reagent cup.In order to prevent overflow and to provide enhanced mixing, it isgenerally preferred that the top and middle reagent compartments arefilled to no greater than about one half their respective capacity.

The bottom receptacle may be filled to virtually its full capacity, ifnecessary. Although the drawings illustrate the use of a reagent cupwith liquid reagents, solid reagents may be employed in one or morecompartments. The quantity of solid reagent which may be added to thetop and middle compartments is dependent, in part, on the physicalproperties of the plastic diaphragm forming the base of thesecompartments.

Turning now to FIGS. 2-4, there is illustrated a method for thesequential addition of prepackaged reagents to a sample of material tobe tested, whereby a chemical evaluation of the material may beperformed. Initially, as illustrated in FIG. 2, a liquid test materialis introduced into the top reagent compartment'by means of a thin tube36. A micropipette or syringe needle may be employed for this purpose.Turning now to FIG. 3, after an appropriate incubation or reactionperiod, a breaker 38 descends and punctures the diaphragm 28 separatingthe top and middle reagent compartments. As the breaker descends, itforces the reagent out of the second compartment up into the firstcompartment, thereby promoting mixing. The breaker then retracts and iswashed. The procedure is repeated for as many reagents as are present.In FIG. 4 washed breaker 38 punctures the diaphragm 26 between themiddle and bottom reagent compartments, thereby effecting mixing of theentire contents of the container.

It will be obvious to those skilled in the art that various breakerdesigns are possible. A preferred breaker design is illustrated inFIG.3. Breaker 38 includes a thin gripping tube 39 which may be knurledor scored to facilitate handling. Cylinder 40 is concentrically disposedabout tube 39. For best mixing results, the diameter of cylinder 40should be less than the diameter of base receptacle 12. The diameter ofcylinder 40 should be preselected such that upon introduction into basereceptacle 12, the contents therein are forced upwardly about the outerperiphery of cylinder 40 and intimately mixed with the contents ofcompartments 30 and 34.

Puncture tip 42 in axial alignment with tube 38 is centrally disposed onthe lower face 44 of cylinder 40. The breaker may be readily fabricated,employing a sharp pointed needle and a cylinder with a hollow core,wherein the diameter of the core is slightly smaller than the diameterof the needle. The cylinder is heated, and while in its expanded state,is slipped over the needle such that the needle point is exposed belowthe bottom face of the cylinder. Thereafter, the cylinder is cooled inorder to form a shrink fit about the needle.

Alternatively, the cylinder may be force-fit over the needle. Further, aunitary breaker may be formed or extruded from plastic materials byemploying a suitable die or mold. The container may be fabricated byconventional extrusion processes employing a tiered die.

The following example is given to further illustrate the novel methodfor the sequential-addition of reagents which have been prepackagedwithin the tiered reagent cup of the invention for the purpose ofperforming a chemical evaluation of a test material and is notlimitative of scope.

EXAMPLE I One drop of pyridine is introduced into the bottom receptacleof the tiered reagent cup of the invention. The bottom receptacle isthereafter sealed by an impervious frangible diaphragm. Two drops of asolution made by dissolving 1 gram of ferric chloride in 100 ml ofchloroform is introduced into the compartment immediately above thebottom receptacle. An impervious frangible plastic diaphragm is thenadhesively sealed above the compartment. One milliliter of chloroform isintroduced into the top compartment. The compartment is hereafter sealedin the manner described hereinabove.

One drop of a liquid suspected of containing phenols or enols is thenintroduced into a thin hollow glass tube by capillary action. An openedend of the capillary tube is forced through the top frangible diaphragmof the reagent container and the unknown liquid is forced into the topcompartment. After about a minute, a pointed breaker is pushed throughthe top and next succeeding frangible seal, thereby mixing the contentsof the top and the next succeeding compartment. The breaker is removedand thoroughly washed, thereafter the washed breaker is forced throughthe frangible seal covering the bottom receptacle, thereby agitating andmixing the contents of the reagent cup. The breaker is removed and thecontents of the cup are examined for a color change typical of phenolsand/or enols.

It will be obvious that the above test procedure is applicable toreagent cups having more than one compartment. If desired, the reagentcup can be fabricated from transparent material so that precipitates,color changes and other physical properties may be observed through thewalls of the cup. A suitable transparent material is the polycarbonateidentified by the trademark Lexan. In any event, the cup material mustbe nonreactive to the reagents employed therein. Further, the sealmaterial should be inert to and impervious to the vapors of any liquidreagents employed therein. It will be obvious to those skilled in theart that serum or other organic materials may be evaluated employingsuitable reagents in a predetermined sequence of addition, as providedby the invention.

Having thus described the invention it is not intended to be limited,except as set forth in the following claims.

I claim:

1. A unitary tiered reagent container adapted for the chemicalevaluation of a material by the sequential addition of pre-packagedreagents thereto comprising:

a plurality of tiered cylinders in abutting axial alignment and having abottom cylinder of smallest diameter and each succeeding cylinder havinga greater diameter than the preceding cylinder;

each cylinder having a radially disposed annular shoulder means forsealingly mounting a frangible partition means dividing the cylindersinto individual compartments.

each of said partition means being supported on said shoulder means andfrangible cover means enclosing the cylinder of greatest diameter andmeans permanently enclosing the end of the cylinder of smallest diameterwhereby a tiered reagent container is formed adapted to housesequentially a reagent in each cylinder in tiered abutting axialalignment.

2. The invention in accordance with claim 1, wherein each compartmentcontains a predetermined quantity of a preselected reagent, whereby asample may be introduced into the compartment sealed by the frangiblecover means and sequentially exposed to the balance of the reagents inthe container by sequentially puncturing the succeeding frangiblepartitions.

3. A unitary tiered container for chemically evaluating a test sample,having discreet compartments, each compartment having a predeterminedamount of a preselected liquid reagent, comprising:

a cylindrical hollow base receptacle permanently enclosed at one end;

a plurality of hollow cylinders in integral, abutting axial alignmenttherewith, each successive cylinder having a greater diameter than thepreceding;

bination with puncture means for successively rupturing each of saidfrangible partition means, said puncture means comprising an elongatedgripping tube having a needle point and a cylinder fixedly securedthereto and in axial alignment therewith, spaced adjacent said needlepoint, wherein the diameter of the cylinder is less than the diameter ofthe base receptacle.

1. A unitary tiered reagent container adapted for the chemicalevaluation of a material by the sequential addition of pre-packagedreagents thereto comprising: a plurality of tiered cylinders in abuttingaxial alignment and having a bottom cylinder of smallest diameter andeach succeeding cylinder having a greater diameter than the precedingcylinder; each cylinder having a radially disposed annular shouldermeans for sealingly mounting a frangible partition means dividing thecylinders into individual compartments. each of said partition meansbeing supported on said shoulder means and frangible cover meansenclosing the cylinder of greatest diameter and means permanentlyenclosing the end of the cylinder of smallest diameter whereby a tieredreagent container is formed adapted to house sequentially a reagent ineach cylinder in tiered abutting axial alignment.
 2. The invention inaccordance with claim 1, wherein each compartment contains apredetermined quantity of a preselected reagent, whereby a sample may beintroduced into the compartment sealed by the frangible cover means andsequentially exposed to the balance of the reagents in the container bysequentially puncturing the succeeding frangible partitions.
 3. Aunitary tiered container for chemically evaluating a test sample, havingdiscreet compartments, each compartment having a predetermined amount ofa preselected liquid reagent, comprising: a cylindrical hollow basereceptacle permanently enclosed at one end; a plurality of hollowcylinders in integral, abutting axial alignment therewith, eachsuccessive cylinder having a greater diameter than the preceding; acontinuously disposed annular shoulder joining the abutting ends of eachsuccessive cylinder; a plurality of frangible, inert, impermeablediaphragms dividing the cylinders into individual compartments, each ofsaid diaphragms supported and adhesively affixed to an annular shoulderand one of said diaphragms overlying the cylinder of greatest diameterand forming a cover for the container.